Detachable container refrigeration system

ABSTRACT

A cryogenic liquid spray refrigeration system detachably mounted on a portable product shipping container for in-transit refrigeration of said container in which refrigeration system requires minimal alteration of said shipping container.

United States Patent Maurer 51 July 11, 1972 1541 DETACHABLE CONTAINER56; References Cited [72] PM wmimvme 3,269, 33 8/1966 Dixon "62/514 73 iUnion Carbide corpora New Ycrk 2,735,277 2/1956 Clark ..62/323 8 NY. on,2,475,755 7/ l 949 Pearson r r "62/514 3,287,925 I 1/!966 Kane r r r r r..62/5 14 Filed: n 1970 328L075 [0/1966 Smyers 62/514 [2]] 75563Priman-Examiner-Meyer Perlin Atromey-Paui A, Rose, Harrie M. Humphreysand John C. 521 0.5.0 ..62/223,62/298,62/449, LeFever 62/5I4 [51] im. ClF25h4l/04 ABSTRACT [58] Field ofSearch "62/222,514, 223, 449, 298, Acryogenic liquid spray refrigeration system detachably 62/323 mounted ona portable product shipping container for intransit refrigeration ofsaid container in which refrigeration system requires minimal alterationof said shipping container.

5Clai|m,3DrawingHgures PATENTEDJULH I972 3.675.439

sum 18F 2 INVENTOR DAVID P. MAURER ATTORNEY DETACIIABLE CONTAINERREFRIGERATION SYSTEM This invention pertains to a refrigerationapparatus for detachable mounting on shipping containers and especiallyshipping containers which are designed to be refrigerated using cold airwhich is introduced and removed from said containcrs by means ofportholes provided therein.

New developments in the technology of shipping refrigerated productsover land and sea have resulted in the rapid growth of containerizedshipping. Containerization as applied to products which must berefrigerated has resulted in the development of numerous techniques forkeeping such containers refrigerated. One such system employs thecirculation of refrigerated air through shipping containers while theyare in transit on shipboard. However, once such refrigerated containersreach their ports of destination some means of maintaining refrigerationin said containers is necessary to prevent spoilage of the container'scontents. For a part-time or intermediate refrigeration system to besuccessful in use with such refrigerated shipping containers thepart-time refrigeration system must require a minimum of alteration ofthe container itself, must detachably mount on the outside of suchcontainer, must occupy a minimum of space, must be virtually free ofmaintenance requirements once installed, and must not require externalpower to perform the refrigeration function. In addition, therefrigeration system must be able to cool down the container veryquickly, maintain uniform temperature control and must require verylittle time to connect and disconnect to the refrigerated shippingcontainer. The use of mechanical refrigeration systems for part-timerefrigeration of such containers has been found to be undesirablebecause such systems are expensive, lack quick cool-down capacity,uniform temperature control and have a high incidence of mechanicalfailure owing to the complexity of the equipment required for mechanicalrefrigeration.

To date, cryogenic in-transit refrigeration systems have beenpermanently attached to the product storage container. However, in viewof the large number of refrigerated containers employed in containershipping and also because a given container may or may not be used toship refrigerated product at all times, the cost both in terms ofequipment required and space lost using permanently installed cryogenicrefrigeration systems renders their use impractical.

The objects of this invention are to provide a cryogenic refrigerationapparatus for use with thermally insulated shipping containers whichapparatus requires a minimum of alteration to the container, attaches tothe outside of said container, occupies extremely little space comparedwith its refrigeration capacity, is virtually maintenance-free, isselfcontained and is capable of providing substantially uniform desiredtemperature within the shipping container.

SUMMARY OF THE INVENTION The objects of this invention are accomplishedby an apparatus for refrigeration of stored product within a portablethermally insulated shipping container having at least one portholetherein, which apparatus comprises a liquefied gas refrigerant storagetank with associated flow control means removably attached to saidshipping container, a refrigerant dispensing means and a temperaturesensing means disposed within said shipping container; a portholeclosure assembly arranged to detachably seal said porthole; andconnection means disposed through said porthole closure assembly andarranged to operably connect said flow control means with saidrefrigerant dispensing means and said temperature sensing means suchthat refrigerant flow is responsive to the temperature sensed by saidtemperature sensing means within said shipping container.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional elevation viewof a thermally insulated container having a liquefied gas refrigerationsystem embodiment of this invention attached to the container's upperforward portion.

FIG. 2 is a perspective view of the container shown in crosssection inFIG. I.

FIG. 3 shows a cross-sectional elevation view of the upper forward portclosure assembly of FIG. 1.

DETAILED DESCRIPTION FIG. 1 of this invention shows a thermallyinsulated shipping container 1 having access doors 2 and containingrefrigerated product 3. A liquefied gas refrigerant storage tank 4 andrefrigerant flow control means 5 are disposed within a clip-on assembly6 which attaches to shipping container I by means of bolts 7. Shippingcontainers typically measure about 8 by 8 by 20 feet and the shippingcontainers preferred for use with this invention are those which haverefrigerant air circulation porthole: such as 8 and 9. A perforatedrefrigerant dispensing conduit 10 is permanently installed in the upperportion of shipping container 1 and preferably is located quite near theceiling to prevent interference with product storage within thecontainer. Temperature sensing means II is removably attached tomounting bracket 12 which is permanently attached to shipping container1 proximate air circulation porthole 8. Porthole 9 which is notnecessary to this invention is shown with a plug therein.

FIG. 2 shows the shipping container 1 of FIG. I with clip-on assembly 6in perspective view. As can be seen, liquefied gas refrigerant storagetank 4 is disposed within clip-on assembly 6 and supplies refrigerant toperforated refrigerant dispensing conduit 10 through porthole IIresponsive to temperature sensing means 11 to maintain refrigeratedproduct 3 at a predetermined temperature.

FIG. 3 shows the portion of shipping container 1 containing porthole 8along with clip-on assembly 6. As can be seen, liquefied gas refrigerantstorage tank 4 and associated flow control means 5 are mounted withinclip-on assembly 6. In ad dition, perforated refrigerant dispensingconduit 10 which is permanently disposed within shipping container I anddetachable temperature sensing means 11 with its associated mountingbracket 12 can also be seen. Porthole closure assembly 13 can be seen indetail for the first time in this figure having a gas pressure reliefmeans 14, such as a mushroomshaped silicon rubber check valve, disposedtherein to relieve excessive pressures generated by evaporatingliquefied refrigerant within shipping container I. Porthole closureassembly I3 is arranged to detachably gas-tightly seal porthole 8 bymeans of sealing gasket 15 and attachment locks 16. Temperature sensingmeans II is connected to temperature sensing means connector 17 by meansof porthole closure assembly connecting wire 18. Temperature sensingmeans connector 17 is rigidly attached to the outside of portholeclosure assembly 13. Porthole closure refrigerant conduit 19 passesthrough porthole closure assembly 13 and attaches at its outer end to arefrigerant connector fining 20 which is rigidly attached to the outsideof porthole closure assembly 13 and at the other end is removablyattached to the perforated refrigerant distribution conduit 10 bycoupling 21. Refrigerant flow control means 5 is detachably connected tosaid temperatul'e sensing means connector fitting 17 by flow controlconnector wire 22 such that refrigerant flow control is responsive totemperature sensed within shipping container I by temperature sensingmeans 11. Said flow control means 5 is operably disposed withinrefrigerant conduit 23 connected at one end to said refrigerant storagetank 4 and at the other end detachably connected to said porflioleclosure refrigerant connector fitting 20. The operable disposition ofcontrol means 5 within refrigerant conduit 23 is carried out byrefrigerant flow control valve 24.

Clip-on assembly 6 is preferably provided with built-in adaptive meansfor receiving a fork lift or crane-installing apparatus, in particularfork lifl channels 25 shown in cross-section in FIG. 3 are providedperpendicular to the axis of liquefied gas refrigeration storage tank 4and at the bottom portion of clip-on assembly 6. Alternatively, one ormore eye bolts 26 are attached to the top portion of clip-on assembly 6such that said clip-on assembly can be raised into position proximateporthole 8 by means of a crane.

In operation, a shipping container such as that depicted in FIGS. 1 and2 can be quickly fitted with a detachable container refrigeration systemof this invention. At this point, porthole closure assembly 13 comprisesattachment locks 16, gas pressure relief means 14, temperature sensingmeans connector 17 with associated porthole assembly closure wire 18,and temperature sensing means 11 as well as refrigeration connectorfitting 20 with its associated porthole closure refrigeration conduit 19along with sealing gasket 15. A workman first reaches in throughporthole 8 and inserts temperature sensing means 11 into mountingbracket 12 which is rigidly attached to the inner wall or ceiling ofshipping container l. The workman then attaches porthole closurerefrigeration conduit 19 to coupling 21. The installation of temperaturesensing means 11 and porthole closure refrigeration conduit 19 may beaccomplished in reverse order if desired. Thereafter, porthole closureassembly 13 is inserted into porthole 8 and locked into place by meansof attachment locks 16. Thereafter, clipon assembly 6 is raised intoposition proximate porthole closure assembly 13 by means of a fork liftor crane and bolts 7 are engaged to securely attach clipon assembly 6 toshipping container 1. At this point, control connector wire 22 isattached to temperature sensing means connector l7 and refrigerationconduit 23 is attached to refrigeration connector fitting 20. At thispoint, refrigeration flow control means can be turned on to beginrefrigeration of shipping container 1.

it should be apparent from the foregoing disclosure that flow controlconnector wire 22 and refrigeration conduit 23 can alternatively be madeso long that their disconnection from the porthole closure assemblywould not be required. Also, it should be clear that flow controlconnector wire 22 and refrigeration conduit 23 can be rigidly connectedto porthole closure assembly 13 at temperature sensing means connector17 and refrigeration connector fitting 20 and the connections torefrigeration flow control means 5 made detachable.

it should be understood that refrigerant dispensing means may compriseperforated refrigerant dispensing conduit which is permanently orremovably installed or can comprise suitable substitutes such as a spraynozzle attached to the inside portion of the porthole closure assembly.The temperature sensing means can comprise an electrical temperaturesensor such as a precision wire wound resistance or a thermistor or cancomprise a pneumatic temperature sensor. The temperature sensor may bemounted on the inside portion of the porthole closure assembly as wellas elsewhere within the storage container.

The generic term connection means" as used herein refers to items 17through 23 inclusive shown in the drawings as well as suitablealternatives to this combination of elements which accomplish thefunction of operably connecting flow control means 5 with therefrigerant dispensing means and the temperature sensing means. Flowcontrol means 5 is arranged to sense the shipping container temperature,compare such sensed temperature with a predetemiined desired temperatureand to actuate the refrigerant flow control valve, shown as item 24 inFIG. 3, when refrigeration is required as indicated by the differencebetween the shipping container temperature and the predetermined desiredtemperature.

What is claimed is:

1. Apparatus for refrigeration of stored product within a portablethermally insulated shipping container having at least one portholetherein, which apparatus comprises a liquefied gas refrigerant storagetank with associated flow control means removably attached to saidshipping container; a refrigerant dispensing means and a temperaturesensing means disposed within said shipping container; a portholeclosure assembly arranged to detachably gas tightly seal said porthole;pressure relief means within said porthole closure assembly;

connection means disposed through said porthole closure assembly andarranged to operably connect said flow control means with saidrefrigerant dispensing means and said temperature sensing means suchthat refrigerant flow is responsive to the temperature sensed by saidtemperature sensing means within said shipping container; and detachablecouplings within said connection means between said porthole closureassembly and said flow control means.

2. An apparatus as described in claim 1 wherein the refrigerantdispensing means comprises a perforated conduit means disposed withinthe upper portion of said shipping container.

3. An apparatus as described in claim 1 wherein the temperature sensingmeans is detachably connected to said shipping container.

4. An apparatus as described in claim 1 wherein said flow control meanscomprises a refrigerant flow control valve operably disposed betweensaid connection means and said refrigerant storage tank; and arefrigerant flow control valve control means responsive to saidtemperature sensing means.

5. Apparatus for refrigerating stored product within a portablethermally insulated shipping container having at least one portholetherein, which apparatus comprises a liquefied gas refrigerant storagetank with associated flow control means removably attached to saidshipping container; a perforated refrigerant dispensing conduit meansdisposed within the upper portion of said shipping container;temperature sensing means detachably disposed within said shippingcontainer proximate the shipping container porthole; a porthole closureassembly arranged to detachably, gas tightly seal said porthole, saidclosure assembly having at least one gas pressure relief means therein;said temperature sensing means being connected through said portholeclosure assembly to a temperature sensing means connector which ismounted outside of said porthole closure assembly; a porthole closurerefrigerant conduit which passes through said closure and attaches atone end to a refrigerant connector fitting mounted outside of saidclosure and is removably attachable at the other end to the perforatedrefrigerant dis ensing conduit within said shipping container; saidrefrigerant flow control means being detachably connected to saidtemperature sensing means connector fitting such that refrigerant flowcontrol is responsive to temperature sensed by said temperature sensingmeans and said flow control means contains a refrigerant flow controlvalve which is operably disposed within a refrigerant conduit connectedat one end to said refrigerant storage tank and at the other enddetachably connected to said porthole closure refrigerant connectorfitting.

1. Apparatus for refrigeration of stored product within a portablethermally insulated shipping container having at least one portholetherein, which apparatus comprises a liquefied gas refrigerant storagetank with associated flow control means removably attached to saidshipping container; a refrigerant dispensing means and a temperaturesensing means disposed within said shipping container; a portholeclosure assembly arranged to detachably gas tightly seal said porthole;pressure relief means within said porthole closure assembly; connectionmeans disposed through said porthole closure assembly and arranged tooperably connect said flow control means with said refrigerantdispensing means and said temperature sensing means such thatrefrigerant flow is responsive to the temperature sensed by saidtemperature sensing means within said shipping container; and detachablecouplings within said connection means between said porthole closureassembly and said flow control means.
 2. An apparatus as described inclaim 1 wherein the refrigerant dispensing means comprises a perforatedconduit means disposed within the upper portion of said shippingcontainer.
 3. An apparatus as described in claim 1 wherein thetemperature sensing means is detachably connected to said shippingcontainer.
 4. An apparatus as described in claim 1 wherein said flowcontrol means comprises a refrigerant flow control valve operablydisposed between said connection means and said refrigerant storagetank; and a refrigerant flow control valve control means responsive tosaid temperature sensing means.
 5. Apparatus for refrigerating storedproduct within a portable thermally insulated shipping container havingat least one porthole therein, which apparatus comprises a liquefied gasrefrigerant storage tank with associated flow control means removablyattached to said shipping container; a perforated refrigerant dispensingconduit means disposed within the upper portion of said shippingcontainer; temperature sensing means detachably disposed within saidshipping container proximate the shipping container porthole; a portholeclosure assembly arranged to detachably, gas tightly seal said porthole,said closure assembly having at least one gas pressure relief meanstherein; said temperature sensing means being connected through saidporthole closure assembly to a temperature sensing means connector whichis mounted outside of said porthole closure assembly; a porthole closurerefrigerant conduit which passes through said closure and attaches atone end to a refrigerant connector fitting mounted outside of saidclosure and is removably attachable at the other end to the perforatedrefrigerant dispensing conduit within said shipping container; saidrefrigerant flow control means being detachably connected to saidtemperature sensing means connector fitting such that refrigerant flowcontrol is responsive to temperature sensed by said temperature sensingmeans and said flow control means contains a refrigerant flow controlvalve which is operably disposed within a refrigerant conduit connectedat one end to said refrigerant storage tank and at the other enddetachably connected to said porthole closure refrigerant connectorfitting.